Question

In a ‘Mahila Bachat Gat’, Sharvari invested ₹ 2 on first day, ₹ 4 on second day and ₹ 6 on third day. If she saves like this, then what would be her total savings in the month of February 2010?

Answer 1

Amount invested by Sharvari in the month of February 2010 are as follows:

2, 4, 6, .....

The above sequence is an A.P

∴ a = 2, d = 4 – 2 = 2

Number of days in February 2010,

n = 28

Now, S_n = `"n"/2 [2"a" + ("n" - 1)"d"]`

∴ S₂₈ = `28/2 [2(2) + (28 - 1)(2)]`

= 14[4 + 27(2)]

= 14(4 + 54)

= 14(58)

= 812

∴ Total savings of Sharvari in the month of February 2010 is ₹ 812.